/*
 * Copyright 2008 Konstantin Triger <kostat@gmail.com> 
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * You may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *  http://www.apache.org/licenses/LICENSE-2.0 
 *  
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package jaque.functions;

/**
 * Counts number of invocations and passes this counter to the invoke method.
 * 
 * @param <Result>
 *            the type of the return value.
 * @param <T>
 *            the type of the only parameter.
 * 
 * @author <a href="mailto://object_streaming@googlegroups.com">Konstantin Triger</a>
 */
public abstract class CountingFunction<Result, T> implements
		Function<Result, T> {
	private int _index;

	// @Override
	public final Result invoke(T t) throws Throwable {
		return invoke(t, _index++);
	}

	protected abstract Result invoke(T t, int index) throws Throwable;
}
